Technological breakthroughs

The synergy between Idemitsu’s prowess in chemical material technology and Toyota’s leading automotive manufacturing capabilities aims not only to commercialize all-solid-state batteries by 2027-2028 but also to usher in a new era for the clean energy industry by utilizing by-products from petroleum refining.

Recently, Toyota Motor Corporation and Idemitsu Kosan Co., Ltd. officially announced a strategic partnership to develop mass-production technologies for solid electrolytes and establish a comprehensive supply chain for this battery type. This is considered a landmark move toward realizing the goal of bringing all-solid-state batteries—the "holy grail" of the electric vehicle (EV) industry—to market in the 2027-2028 period.

From Refinery By-products to Breakthrough Energy Materials

The core of this collaboration is sulfide-based solid electrolytes. In the field of materials science, sulfide is regarded as the most promising material due to its softness, high adhesiveness, and flexible ion conductivity. These characteristics not only help batteries achieve higher power output but are also highly suitable for mass-production lines.

The most surprising element is the origin of this material. Idemitsu has successfully researched the production of lithium sulfide—an intermediate material for solid electrolytes—by utilizing by-products generated during the petroleum refining process. With over 20 years of research experience (since 2001), Idemitsu has transformed what was once considered "waste" from the fossil fuel industry into a key solution for the carbon neutrality roadmap.

To realize this ambition, Idemitsu is continuously expanding its production capacity. The company is currently increasing the capacity of its small pilot facility (announced in June 2023) and is aggressively proceeding with plans to build a large pilot facility (announced in April 2022). These production links play a decisive role in ensuring a stable material supply for the commercialization of solid-state batteries in 2027-2028.

Solving the Toughest Challenges: Durability and Mass Production

At the press conference, Mr. Koji Sato, President and CEO of Toyota, frankly pointed out that the biggest challenge for solid-state batteries over the past decades has been durability. “Repeated charging and discharging cause cracks in the solid electrolyte, rapidly degrading battery performance,” Mr. Sato shared.

However, through repeated trial and error since 2013, the combination of Idemitsu’s flexible, highly adhesive material technology and Toyota’s battery manufacturing technology has created a new material with superior crack resistance. By combining this electrolyte with the Toyota Group's advanced cathode and anode materials, the solution to balancing high performance and durability has finally been found.

All-solid-state batteries possess outstanding advantages over current liquid lithium-ion batteries: shorter charging times, longer cruising ranges, and extremely stable performance under high temperatures and voltages. This allows EVs to meet diverse needs, from high-performance sports cars to commercial vehicles requiring frequent quick charging.

A Strategic Three-Phase Roadmap

To ensure the project moves beyond the research stage, both parties have established a task force of dozens of leading experts in technology, procurement, and logistics, implementing a strict three-phase plan:

1. Phase 1 (Current): Focus on optimizing sulfide solid electrolytes in terms of quality, cost, and lead times at small-scale pilot facilities.

2. Phase 2 (Preparation for Commercialization): Idemitsu will operate large-scale pilot facilities to perfect mass-production technology. Meanwhile, Toyota will focus on developing Battery Electric Vehicles (BEVs) integrated with solid-state batteries, ensuring a market launch in 2027-2028.

3. Phase 3 (Global Mass Production): Based on the results, both companies will explore expanding to full-scale mass production and global commercialization.

An Ambition to Set Global Standards from Japan

Mr. Shunichi Kito, President of Idemitsu Kosan, affirmed: "Changing the future of cars also means changing the future of energy." The combination of Toyota's manufacturing power and Idemitsu's material chemistry expertise—two entities leading the world in patents related to solid-state batteries—is expected to create breakthrough innovations with Japanese "DNA."

This event is not only good news for EV consumers but also a valuable lesson for global chemical and energy corporations on maximizing the value chain from oil and gas to transition toward clean energy. This cross-industry handshake between a leader in energy and a leader in manufacturing is the key to realizing visions that once seemed like distant dreams.